The present invention relates to a new and improved apparatus for outfeeding and stacking sheet metal sections or cuttings or the like which are formed following a sheet metal feeding or infeed table associated with sheet metal shears or cutter means.
In its more particular aspects the apparatus of the present development is of the type comprising a cutting blade or cutter, supporting rake or grate means for receiving the sheet metal sections or cuttings, abutment or stop means structured to be horizontally displaceable relative to said supporting rake means in accordance with the desired width of the sheet metal section or cutting, and a roller platform designed to be vertically adjustable and serving to carry pallets or containers which receive stacks of said sheet metal sections or cuttings. For stacking the sheet metal sections or cuttings--sometimes referred to as blanks--deposited on the supporting rake means immediately after the cutting operation, the supporting rake means including the abutment means are arranged to be selectively positioned above one of a number of stacking locations during a first step of a horizontal movement and, for releasing the sheet metal section or cutting, the supporting rake means can be displaced beyond said stacking location during a second step of said horizontal movement in the same direction.
Sheet metal shears or shear arrangements as known, for example, from German Patent Publication No. 2,840,668, comprise stacking means arranged at the rear side of the cutting blade or cutter. The stacking means serve to selectively stack the cut-off sheet metal strips at different places in such a manner that different stacks can be served, which are arranged, for example, in the order of the size of the sheet metal strips, or such that in the case of constant strip size a number of equal stacks can be served immediately one after the other for better space utilization. The cut-off sheet metal strip is placed upon a supporting grid or grate following the cutting location and is pushed onto a chain conveyor by means of pushing or pusher arms extending between the parallel rods of the supporting grid. The sheet metal strips are conveyed to supporting rake means structured to be moved horizontally across the stacking surface by means of cams mounted on the chains of the chain conveyor. The supporting rake means is accelerated from a rest position to the speed of the chain conveyor shortly prior to the time that the trailing edge of the sheet metal section leaves the chain conveyor. The supporting rake means is retracted together with the sheet metal section towards an abutment or stop. To gently decelerate the sheet metal strip the abutment is accelerated to the speed of the sheet metal strip on the supporting rake means prior to being contacted by the leading edge of the sheet metal strip and is, then, decelerated until it comes to a standstill. Approximately at the point of transition from the acceleration phase to the deceleration phase the sheet metal edge contacts the abutment and the sheet metal strip is gently decelerated to standstill together with the abutment while the supporting rake means moves further at a constant speed and the sheet metal strip falls onto the intended stack. The drop or fall height is maintained approximately constant by means of a vertically adjustable roller platform upon which, for example, there rests a pallet for receiving the sheet metal strips.
It is a disadvantage of this design that the stacking means must work with small accelerations and small velocities in order to prevent the sheet metal sections from sliding upon the supporting rake means and to neatly stack the same. A further disadvantage is the relatively large space required for the stacking means including the supporting grid, the chain conveyor and the supporting rake means which are arranged following the cutting plane. It is additionally a drawback of this system design that scrap sheet metal obtained during trimming the sheet metal plates indiscriminately falls onto the floor between the cutting plane and the supporting grid and must be manually removed in a troublesome and cumbersome operation.